4Roberts C, Lawson M, Newble D, Self A, et al. The introduction of large class problem-based learning into an undergraduate medical curriculum:an evaluation[ J]. Med Teach, 2005,27: 52-53.
5Distlehorst LH, Dawson E, Robbs RS, et al. Problem-based learning out- comes:the glass haf-full[J] .Acad Med,2005,80:294-299.
6Malathi S. Michael W. Frazie S. et al. Comparing Problem-Based Learning with Case-Based Learning: Effects of a Major Curricular Shift at Two Insti- tutions[ J]. Acad Med, 2007,82: 74-82.
7Slavin SJ, Wilkes MS, Usatine R. Doctoring III. Innovations in education in the clinical years[J]. Acad Med, 1995,70:1091-1095.